not to mention anyone with a magnet is gonna know there is bondo every where over the car.
You can punch the quarter panel and make bondo shoot out the majority of the time (seen it happen on accident, took out a huge chunk of paint to haha) if its not attached 100%
I personally think lead is easier to work then bondo is. with a hell of a lot less mess, its stronger.. will last longer, has a smoother finished look and you can do lots of creative things with lead that isn't possible with bondo.
theres a reason they call 'em Lead Sleds.
But anyways its a really awesome way to just cut out the rust completely, lay down a piece of sheet metal, stitch weld it together, then lead over the edges until its nice and smooth.
Also works flippin awesome at covering up dents,creases and knicks.
(its cheap as s@#t to)